Silanes are useful in diverse industries from construction to automotive, marine to sporting goods, and electronics to aerospace. In these industries, silanes function as, among other things, coupling agents, adhesion promoters, stabilizers, hydrophobing agents, dispersing agents, moisture scavengers, and crosslinking agents. In addition to being useful alone, silanes may function as the building blocks of other materials such as silicones.
Silanes are typically made commercially by what is commonly known as the “direct process.” The direct process was first introduced by Rochow and has since been modified to optimize and control the silanes produced by the process. Generally, the direct process involves the reaction of silicon metal with an organic halide, such as methyl chloride, in the presence of a metal catalyst and promoters to produce a mixture of silanes. The process can produce halosilanes, organohalosilanes, as well as organohalohydrosilanes, but the predominant silane produced industrially by the direct process is dimethyldichlorosilane. Because the predominant silane produced is dimethyldichlorosilane, there can be shortages of other silanes, and methods of controlling the direct process to produce other silanes besides diorganodihalosilanes are desired.
The present inventors have found a new method to produce organohalohydrosilanes. The method allows better control of the direct process to provide, in some embodiments, increased selectivity for organohalohydrosilanes, improved ratio of the specific organohalohydrosilanes produced, and improved methyl efficiency.